# How much knee flexion in depth jumps?

i recently video taped my depth jumps, i was doing ground contacts of .2-.3 seconds, but i noticed my knee flexion got as high as maybe 100-110 degrees

My question is how much knee flexion should i be aiming for in depth jumps?
Does this signify something such as weak eccentric strength?

thank you

Got any photos/video? 100 degrees sounds like a lot. How high is the box?

i think my interpretation of 100 degrees may be different from yours, my lowest point is well above parallel but still, in my opinion, significant knee flexion

i will be posting a video shortly, thank you for you help.

Didn’t Prof. Verkhoshansky come out and say that optimal jumps have a longer coupling time?

sorry, but i am a beginner with only basic knowledge, so… what does that mean?

Those look good to me.

I think coupling time is the time period between the eccentric and concentric portion of a jump. Not easy to measure. You could generalize and say that the best jumps have a slightly conservative contact time (just like the jumps in your vid).

The degree of knee flexion as well as coupling time must be specific to the reasoning behind the inclusion of depth jumps to the training program.

To discuss such factors void of the context of addressing the target of training is a nebulous undertaking that will render all subsequent debate meaningless.

Limiting this question to knee flexion and coupling time, what specific training effects are realized by changes in these two variables?

He’s probably comparing force/ ground time trade off. Simple chemistry if ground time is too long kinetic energy dissipates as heat.

considering where in the amplitude the greatest magnitude of force is produced we know that the knee position held during ground contact on depth jumps is where, plus or minus a small degree, the most significant gains will occur. As a result, the knee position must be specific, as I stated, to the reason for including the depth jumps in the program.

Examples:

• a ski jumper would match the knee position during take off on the ramp
• an NFL prospect training the counter movement vertical jump for the combine would match the knee position they typically descend to during a counter movement
• a volleyball player would match the knee position they typically descend to during sport play prior to blocking/hitting at the net, or serving
• a T&F jumper would match the knee position they descend to prior to take off in the single leg variants
• and so on

Regarding coupling time, this must also be specific to the sport being trained for regarding the ground contact times associated with particular aspects of competition in which explosive jumps occur.

If the coupling time of the depth jump in training far exceeds that which the athlete has time for during that aspect of their discipline then the reliability of the transfer becomes diminished.

Again, we must acknowledge the reason for using the depth jump. If the reason is rooted in improving the performance of a specific aspect of sport from a kinematic and neuromuscular standpoint then a greater degree of dynamic correspondence must be satisfied in order to ensure positive transfer.

Alternatively, if the goal is less concrete then less criteria need be satisfied in order to attain positive transfer. One such example might be the use of the depth jump as a neuromuscular primer for a subsequent tonic or speed strength activity.

I struggle to grasp this concept - if you are so specific with the coupling time then why bother even to even include depth jumps if the sport is providing sufficient stimulus? If depth jumps are a new stimulus / provide a significant intensification then something must give i.e., greater forces therefore greater coupling time, knee angle etc?

Good point hence it is a matter of intergration of the entire program rather than the coupling time / specificity?

Confusing

What must be understood is that the depth jump, and the stress response it imposes, is the overload. The method of its execution is specific to the intended training effect.

No sport, in and of itself and through the course of time, provides a sufficient enough stimulus to promote the adaptations necessary to attain sport mastery. hence the significance of supplementary training that includes work separate from the competition exercise itself, as similar as it may be to the casual observer regarding camps that have greatly minimized the training means (ergo Abadjiev).

Again, what must be scrutinized is the reasoning for including depth jumps in the program. Once the proper justification is in order any concern over the particularities of its execution are an afterthought- as that discussion is fundamental to validating their use in the program in the first place.

So much over complication. I’ll make it simple. The guy is a HS 12.5 100m sprinter. Depth jumps probably aren’t a great idea at this point in his career. However he is at least performing them in a correct manner that will affect some phase of his 100m race.

Its the world we live in, over complication is the key to success in life!

well put, when i started this , i was just wondering if i was doing them correctly

Not from my point of you. My points are irrespective of this individual’s execution of the exercise.

What I aim to illustrate is the monumental significance of optimal exercise selection regarding intensive training components.

The discussion is far removed from talk of auxiliary work that has a negligible impact on readiness for intensive work.

Depth jumps, being one the most intensive forms of exercise, deserve a great deal of scrutiny in my view.

Regarding the low qualification level (12.5) the discussion deserves even greater scrutiny because as you eluded to, the fact that depth jumps are being performed at all is extraordinarily unwarranted.

This is why depth jumps shouldnt be used by lower level sprinters.

Out of curiousity, what is the appropriate “level of sprinter” to use depth jumps?
Are they okay for a 11.2-10.9 guy (completely self-centered question).

Depth jumps are overrated by most people. They are good but just another tool that is possibly a bit better than other exercises that are similar in nature. Tuck jumps, box jumps, hurdle hops, depth jumps…all are similar in nature. That is unless you’re looking at verkho’s charts that make it appear that depth jumps are 20x more effective than any other means of training.

That being said, I would look at training age instead of performance to determine when in a career to implement depth jumps or shock training. Depth jumps are pretty much the end of the road on the intensity scale so don’t use them too early or too frequently.

Many a great sprinter has been produced without any significant use of depth jumps. If you’re talking about a jumping sport (volleyball, athletics jumps, etc) then they might have a more prominent role.